P0212 - Cylinder 12 Injector Circuit Malfunction
Last updated:
System
Powertrain (Engine & Gearbox)
Related Fault Codes
Technical Description
P0212 is a diagnostic trouble code (DTC) for 'Cylinder 12 Injector Circuit Malfunction'. The PCM (Powertrain Control Module) monitors the continuity and voltage of the injector circuit. When the injector driver is pulsed, the PCM expects to see a specific voltage drop and inductive kickback. If the PCM detects a voltage that is out of range or no current flow when the driver is commanded on, P0212 is stored. On most modern vehicles, this will trigger a 'limp home' mode or cylinder deactivation to protect the catalytic converter from unburned fuel.
Possible Causes
Faulty fuel injector (internal open circuit in solenoid coil)
Damaged wiring harness or corrosion in the injector connector
Loose connection at the PCM/ECU
Internal PCM/ECU driver failure
Symptoms
Recommended Solution
- VISUAL INSPECTION: Inspect the wiring and connector for injector 12. Look for frayed wires, heat damage, or oxidation in the pins.
- RESISTANCE TEST: Unplug the injector and measure resistance across the terminals. Most injectors should read 11–16 Ohms. If it reads O.L (open loop), the injector is faulty.
- CIRCUIT TEST: Check for 12V supply at the connector with key on. Use a Noid Light to verify the pulse signal from the PCM during cranking.
- CONTINUITY TEST: Perform a continuity test on the signal wire back to the PCM to rule out a broken wire in the harness.
- COMPONENT REPLACEMENT: If the injector fails the resistance test, replace the injector and clear the codes.
Mechanic's Tip
Before replacing expensive components, always double-check wiring and connections. 80% of all sensor faults are actually due to corroded contacts or broken wires.
Do you also have
other fault codes?
See how P0212 connects with your other fault codes. Our advanced analysis tool identifies causal relationships and root causes directly.